International Agency for Research on Cancer (IARC) - Summaries & Evaluations

CHLOROTHALONIL

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Chlorothalonil was tested for carcinogenicity in mice and rats by
administration in the diet; it produced adenomas and adenocarcinomas
of the kidney in rats. No evidence of carcinogenicity was found in
mice.

No published data were available to evaluate the teratogenicity
of this compound to experimental animals.

Chlorothalonil was not mutagenic in two fungal systems and was
reported to be nonmutagenic in Salmonella typhimurium. Available
data on other systems are inadequate, and no overall evaluation of the
mutagenicity of chlorothalonil could be made.

5.2 Human data

Chlorothalonil was introduced commercially in 1969. Its
production, formulation and use as a fungicide in agricultural and
industrial applications are potential sources of exposure, both of
workers and of the general population.

No data were available to evaluate the teratogenic or chromosomal
effects of chlorothalonil in humans.

No case report or epidemiological study of the carcinogenicity of
chlorothalonil alone was available to the Working Group; however, it
should be noted that the period since introduction of this compound
may be too short for a carcinogenic effect to be detected in humans.
(See also the section 'Cancer Epidemiology of Pesticide Manufacturers,
Formulations and Users', in this volume).

5.3 Evaluation

Results of one experiment in rats provide limited evidence that
chlorothalonil is carcinogenic to experimental animals. No data on
humans were available.

The available data are insufficient to evaluate the
carcinogenicity of chlorothalonil to humans.